1. Field of the Invention
The present general inventive concept relates to a target system and method to be used in photogrammetry, and in one particular embodiment, to a target holder having an aperture at least partially therethrough to precisely position a target assembly therein for use in determining geometric properties of an object. In another embodiment, the general inventive concept relates to a target holder including an annular protruding rim and a generally flat surface for placement of a target piece (such as a target paper material). In still another embodiment, the general inventive concept relates to a method of placing a target piece on a target holder.
2. Description of the Related Art
A large number of industries require precise and accurate measuring for a number of applications such as production, manufacturing, and process control. In many such applications, measurement errors on the order of even one ten-thousandth of an inch can be critical. Instruments such as laser trackers, scanners, associated targets and the like are particularly well suited for such applications because they provide extreme precision and accuracy.
Retro-reflective photogrammetric target systems have been designed, such as the system disclosed by U.S. Pat. No. 5,073,005, the entire disclosure of which is incorporated herein by reference, for precise measurement application. Nevertheless, the target structure of U.S. Pat. No. 5,073,005 provides significant challenges during manufacturing, as minor imprecision during the assembly of a single component (such as a mask over a reflective material of the target) can result in significant inaccuracy of the target during usage. Therefore, it would be desirable to provide a target structure that can be assembled with less possibility of resulting in inaccuracies of the target during usage.